1,720,986 research outputs found
Oxidative stress and vascular stiffness in hypertension: A renewed interest for antioxidant therapies?
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effects of olive oil on blood pressure: Epidemiological, clinical, and mechanistic evidence
No full textThe increasing access to antihypertensive medications has improved longevity and quality of life in hypertensive patients. Nevertheless, hypertension still remains a major risk factor for stroke and myocardial infarction, suggesting the need to implement management of pre-and hypertensive patients. In addition to antihypertensive medications, lifestyle changes, including healthier dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet, have been shown to favorably affect blood pressure and are now recommended as integrative tools in hypertension management. An analysis of the effects of nutritional components of the Mediterranean diet(s) on blood pressure has therefore become mandatory. After a literature review of the impact of Mediterranean diet(s) on cardiovascular risk factors, we here analyze the effects of olive oil and its major components on blood pressure in healthy and cardiovascular disease individuals and examine underlying mechanisms of action. Both experimental and human studies agree in showing anti-hypertensive effects of olive oil. We conclude that due to its high oleic acid and antioxidant polyphenol content, the consumption of olive oil may be advised as the optimal fat choice in the management protocols for hypertension in both healthy and cardiovascular disease patients
Microarray analysis of human umbilical vein endothelial cells treated with the omega-3 fatty acid docosahexaenoic acid (DHA) highlights new anti-atherosclerotic and anti-angiogenic properties for fish
No full textHigh intakes of omega-3 fatty acids have been associated with systemic anti-inflammatory effects and cardiovascular protection, but the molecular basis for these effects remains incompletely defined. Using a DNA microarray technology we investigated the early gene expression profile of human vascular endothelial cells conditioned by DHA under proinflammatory conditions.
Methods. Human umbilical vein endothelial cells (HUVEC) were treated with 50 μmol/L DHA for 48 hours and then stimulated with 5 ng/mL IL-1beta for 3 hours. Total RNA was extracted, and qualitatively and quantitatively analyzed with a NanoDrop Spectrophotometer and an Agilent Bioanalyzer before RNA labeling and purification. Gene expression profiling was performed with an Agilent Whole Human Genome Oligo Microarray covering 41 000 unique genes and transcripts. Slides were scanned with the Agilent’s scanner and images processed using Agilent Feature Extraction software. The raw data were further processed with the GeneSpring® 10 software and differentially expressed RNA identified using Benjamini and Hochberg False Discovery Rate with a p-value <0.05. Functional and network analyses were identified by the Ingenuity Pathways version 8.0 Analysis.
Results IL-1 stimulation significantly changed the expression of 1474 genes: 815 had decreased, while 659 had increased. Out of the 659 IL-1-upregulated genes, DHA significantly attenuated the expression of 88 genes. The Ingenuity pathway analysis software indicated immunological-, inflammatory- and atherogenic pathways as the most affected. In particular, we identified new target molecules involved in atherosclerosis, including tubulin beta polypeptide[TUBB]2 A and phosphodiesterase[PDE]5A; and in angiogenesis, including transforming growth factor[TGF]-beta 2 and chemokine (C-X-C motif) ligand 10.
Conclusions: DHA widely affects endothelial gene expression; the identification of novel genes susceptible to regulation by DHA will certainly improve our understanding of mechanisms by which omega-3 fatty acids may prevent or attenuate human chronic diseases including atherosclerosis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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